I used to have pet rats and I loved them to bits. Cute little things.
Then I moved to Alberta, where it's supposedly 'rat free' (legit. It's illegal to own them, and if you see them you have to call this service to come and kill them. It's ******* ridiculous) and when I tell people I had pet rats they look at me like I'm on meth.
How the hell do you keep an entire province rat free?

Well domesticated rats are fine, but non-domesticated are full of disease and just don't look good. And unfortunately some people aren't the most responsible with pets like that that can be just 'set free' when they don't want them anymore.

I've heard that rats are social creatures and get lonely if you keep them on their own, so it makes sense that all the people who are showing their rat pictures would show both of them (someone tell me if the rat thing is ******** btw)

It's not, rats have a tendency to get lonely if not kept in pairs. However, if you only have one it's fine as long as you keep it company every day, have it up and cuddle it for a few hours a day. If you have only one rat it needs a lot more interraction than if you have two.